I made this a while back to use up some of my button stash, and I quite like how it turned out. It's an easy craft to make and can be done even while sitting on the couch watch TV if you're so inclined.
A safety pin
Twine/thick thread. (I'm using crochet thread)
Cut three long pieces of thread of equal lengths, and tie together. Feed a button onto a piece of thread (in through one hole in the back, and back through another hole) and start braiding. Every inch or so, braid in another bead the same way.
When you're almost at the end, knot off the braid, and then put another knot an inch down the thread to make a loop. To close, slip the first button through the loop.
You can wear it as a necklace or loop it a few times for a bracelet, which I think looks really good since the extra layers of buttons hide much of the twine. and makes a wonderful sound when they clink together.
Done and done! Easy peasy, amirite?